B6100 w/ Loader+Backhoe

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
486
248
43
San Antonio Texas
Another thing I had to fix was 'everything about the throttle linkage'.

Multiple issues:
  • The throttle pedal shaft was broke loose from the arm it rotates and spun freely inside, thus the pics of the throttle pedal hanging loose way before the floorboard.
  • The inner and outer layers of the throttle linkage under the dash were seized together, meaning that if the pedal were hooked up it would also move the hand lever, etc. The two are supposed to move freely of each other.
  • The pedal return spring on said bracket was fatigued enough that it had a bunch of slack and no preload at all.
  • The rod connecting the throttle linkage under the dash to the top of the injection pump was bent, and the small cotter pin holding the rod to the throttle arm under the dash was bent over, seized in place, and there was no washer, so the rod would frequently fall out of the arm.
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First thing was rejoin the pedal shaft to the arm it rotates. I took the lazy way out here and didn't even inspect for a sheared roll pin or whatever the actual reason was that these two parts spun loose. I just put both sides in the correct position and buzzed it in place while laying on the ground next to the tractor. Also seen is washer and hairpin i put in the brake/clutch/diff lock rods. I tried to replace nearly all cotter pins with hairpins on the rod linkages on the tractor. As a mechanic i spend innumerable seconds walking back and forth between toolboxes and workpiece getting tools and i like that with a hairpin you can usually get it out and back in with no tools if you have to. Some places need cotters but these locations are well protected and i dont expect the hairpins to ever get pulled off accidentally.

Also, if you didn't know these tractors have grease fittings on the pedal shafts, you should go grease yours!
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So i dont remember how but i pressed or hammered this apart and wire wheeled the inner and outer surfaces clean of rust.
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I really love these little 1/4" hex 'pipe cleaner' style wire wheels that i can stick in my cordless impact and zing up to ludicrous speed. I used them extensively on this tractor since i fixed just about every damn thing that pivots, including the hood. 😂
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Before reassembling the bracket i also drilled a new hole for the return spring to pin into to take all the slack back out of it. Of course, since i am insufficiently (apparently..) medicated for ADHD i usually forget what i was doing before i finish doing it, so after drilling the new hole i convinced myself i had everything backwards and drilled another hole on the other side. Then i took it to the tractor and found out i had it right the first time. 🙄:cautious:
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Next i fixed the bent throttle rod. I removed the adjustable bracket from the threaded section at the end of the rod, which was bent right outside where the locknut had been on the shaft. Unfortunately i dont have a pic of the bend before repair, so this might be a bit abstract.. Its tricky to push real hard on a small threaded section of something without damaging the threads. In order to prevent damaging the threads while straightening the rod, i trapped a box end wrench between two flanged nuts. I then held the unthreaded section of the rod, and unbent the threaded section by prying through the open end of the wrench. I usually do this trick the opposite way by slipping the open end over a pipe/rod and then prying in the boxed end. In this process, i was pushing on the threaded rod through the nuts themselves which fit perfectly to the threads and avoided putting any damage on this small part.
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Next was to get the seized cotter pin out of the small bracket that goes onto that threaded rod.
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I trimmed it close to flush, then ground it down to truly flush because i knew it would be very hard for a tiny punch (or worst case, drill bit) to 'find' and enter the original hole if it was balanced on top of an oddly shaped lump sitting proud of the hole. This too will quickly surface rust until it blends in. 😂
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Next i found a set of vise grips to serve as a tiny vise and prevent the part from rotating when i hit it.
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Flawless victory. You can see that as soon as i touched the part with my greasy gloves the fresh grind marks practically disappeared.

Continued..
 
Last edited:

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
486
248
43
San Antonio Texas
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New hardware and back to the tractor. I used those same two plated flange nuts instead of the rusty plain nuts that came off, and adjusted the linkage.

The rod i had to straighten was bent at the thread and also more gradually along its length because it was misadjusted. Whenever the lever on the injection pump end maxes out, you need the lever at the dashboard end to max or nearly max out as well. If the injection pump end won't go any further but the dashboard end you are pushing with your hand or jamming with your foot can go further, then guess what? You bend the rod! Heck, you may even break the arm loose on the pedal shaft, lay over the cotter pin and push the bracket right past it and pop the linkage apart in the process. It probably took 'multiple attempts' to get it to this point. 🙄 I mean jeez, who in the crap was running this thing?!

On the other hand, many tractors have a coil spring 'overtravel' mechanism on the rod linkage so that if you max out the engine end of things you start compressing a spring instead of bending and breaking things. If this tractor had that it probably only would have needed repair from age/sitting (seized/rusty) but wouldn't have as much or any damage from hamfisted (&footed) operators.

So, it was adjusted so as not to be able to force it past max throttle and put the rod in serious compression and bending. Anyway, now nothing is seized, its adjusted properly, the foot pedal works, and the return spring properly returns the pedal.